Great Lakes' Ice Cover Nears 1979 Record

All the polar air this winter has frozen the Great Lakes to an extent not seen in 35 years. Scientists say the record for ice coverage, set in 1979, could soon be broken. That year, nearly 95 percent of the Great Lakes were covered with ice. As of yesterday, ice coverage was at 92 percent.

LINDA WERTHEIMER, HOST:

We wondered about the implications of all that ice, beyond some daredevils taking their chances on it. For one thing, we were told that way up on the Upper Peninsula of Michigan it's as if someone flipped a switch and turned off the snow.

We asked George Leshkevich about that. He is a physical scientist with the National Oceanic and Atmospheric Association.

GEORGE LESHKEVICH: The ice covers the waters. It reduces evaporation and therefore of the chance of lake affects snow.

WERTHEIMER: The Coast Guard says that it's been four times as busy with its ice cutters - that's four times more than last year. I guess that means that there is not much shipping on the Great Lakes right now.

LESHKEVICH: Yes, the shippers and the Coast Guard are having a very hard time. And a lot of ships were beset in the ice earlier this season and needed Coast Guard assistance to break them out, and escort them to port. I think now it sounds like they are not moving unless they have a Coast Guard icebreaker escort.

WERTHEIMER: So what does that mean for the cities along the lakes, the people who are trying to ship the goods? Is this causing any kind of dislocation?

LESHKEVICH: Certainly a delay; a trip that might, you know, have taken a day or two now is perhaps double or more.

WERTHEIMER: Are there good things to be said about all this ice? Is there some upside?

LESHKEVICH: Well, sure. You know, considering the ecology, for instance, whitefish require a stabilized cover over their spawning beds during the winter. Otherwise the spawning beds are susceptible to winter storms.

WERTHEIMER: So we can look for more whitefish? What about - my understanding is that this might even be good for like Michigan cherries.

LESHKEVICH: Absolutely. If the ice lasts long into the spring, which it looks like it may do, then the blossoms - the cherry blossoms, apple blossoms - probably won't come out until later. And therefore reduce the possibility of killing frost.

WERTHEIMER: So they'd be more likely to make it to fruit?

LESHKEVICH: Yes. Yes.

WERTHEIMER: It's March already. It's almost spring, what do you think? You think this ice is going to stick around?

LESHKEVICH: Right now, it appears that that'll be the case. We are supposed to have some warming - a warming trend at least in the lower lakes. And it depends on the winds, too, because the winds have an effect on the ice cover. It can break up the ice and move it around.

WERTHEIMER: I have no experience of the Great Lakes when the ice breaks up. But I can remember years on the Potomac River where the ice would start to break, and there would be these incredible noises. Does that happen on the lakes?

LESHKEVICH: Yes. Yes. That's pressure cracks and pressure ridging where two ice sheets come together, and they push up the ice into a ridge. It is kind of exciting to hear. I mean just the vast expanse of the ice cover is just, you know, fascinating to see and it's fascinating to hear.

WERTHEIMER: George Leshkevich is with NOAA's Great Lakes Environmental Research Laboratory. He joined us from Michigan Radio.